BIOCHEMICAL
MEDICINE
14, 347-354 (1975)
Monoamine Oxidase Activity in Blood Platelets from Patients with Cyclophrenic Depressive Syndromes JERZY LANDOWSKI, Departments
WIESZAWA
of Psychiatry Medical
UYSIAK,
AND STEFAN
and Clinical Biochemistry, Academy, 80-21 I Gdatisk,
Institute Poland
ANGIELSKI of Pathology,
Received March 21. 1975
Genetic and clinical investigations (l-5) have made it possible to distinguish between two basic forms of cyclophrenia, the bipolar and the unipolar. The differences are also of pharmacological (6), neurophysiological(7), and biochemical (8, 9) nature and are related, among others, to MAO activity in blood platelets, which differs in bipolar depressed patients from that in unipolar depressed patients (10). It was demonstrated in investigations in which tryptamine was used as substrate for the enzyme. On the basis of Severma’s investigations (11, 12)) it may be suggested that some of the observed changes in monoamine oxidase activity (MAO) could be related to the chemical structure of the substrate used. It has, therefore, seemed of interest to use a substrate other than tryptamine to compare the activities of the platelet enzyme in the two basic groups of cyclophrenic depression. In this study we used benzylamine which is more hydrophobic than tryptamine. METHODS AND MATERIALS
MAO activity in blood platelets was studied in 48 patients hospitalized with diagnose of cyclophrenic depression (13 bipolar, 35 unipolar). In the group of bipolar depression (six women and seven men), were included patients with a history of at least one manic episode requiring treatment. The group of unipolar depression (20 women and 15 men), included patients who fulfilled the Pert-is criterion (2) and had at least three depressive episodes with absence of the manic or the hypomanic. The activity of the enzyme was determined during peak intensity of clinical depressive symptoms. The controls were patients (15 women and 15 men) with disorders of nonpsychotic nature (neurosis, brain organic damage). The patients received no medication for at least 1 week prior to the start of the study. Mean ages in the different groups were: controls-46.0 years, bipolar48.7, and unipolarA9.3. 341 Copyright 0 1975 by Academic Press. Inc. All rights of reproduction in any form reserved.
348
LANDOWSKI
ET AI
Blood samples were collected from fasting overnight patients at 8 AM into plastic test tubes containing 0.1 mmole EDTA. A suspension of blood platelets was obtained from 20 ml of whole blood by the method of Shulman et al. (13) in modification of Robinson et (11. (14). The final blood platelets residue was suspended in 1.1 ml of saline with addition of Triton X-100 at final concentration of 0.5%. MAO activities in blood platelets were determined by the method of Robinson et al. (14) with benzylamine as substrate. Incubation mixture contained in final volume of 1.5 ml:0.24 mmole of potassium phosphate buffer, pH = 7.2, 12 pm of benzylamine, and a blood platelets preparation corresponding to 0.4-0.5 mg of protein. The reaction was carried out at 37°C for 2 hr and was stopped by addition of 0.15 ml 6% HClO,. The benzaldehyde formed as a product of the reaction was extracted into 2.0 ml of cyclohexane in which the absorption changes were measured spectrophotometrically at 242 nm wavelength. The activity of the enzyme was expressed as nmoles of benzaldehyde formed per milligram of protein per hour. The reaction rate measured by the amount of the benzaldehyde formed was linear with reaction time and proportional to the amounts of protein. The amount of protein was determined by the biuret method (15) with bovine serum albumin as standard. RESULTS MAO Activity in Blood Platelets the Menstrual Cycle
during
The activity of the enzyme was determined at the mid-cycle and on the last day of the menstrual cycle in women aged 25 to 33 yr, having regular menstrual cycles and not displaying any symptoms of hormonal disorder. Table 1 shows that there were no significant changes in MAO activity during the menstrual cycle. Therefore, the phase ofthe cycle was not taken into consideration in the further course of the study. Sex-Dependence
of MAO Activity
in Blood Platelets
Comparison of the activity ofthe enzyme between the men and women of the control group (Table 2) revealed no statistically significant differences. In the further course of the study, the men and women of the control group were therefore treated as one unit. MAO Activity in Blood Platelets from Patients with Cyclophrenic Depression
As can be seen in Table 3, the activity of the enzyme in bipolar depressed patients (22.9 _C 7.9 nmole/mg proteimhr) was statistically significantly
CYCLOPHRENIC
DEPRESSIVE TABLE
PLATELET
MAO ACTIVITY
SYNDROMES
349
1
IN WOMEN
DURING
THE MENSTRUAL
CYCLE
MAO activitp Number of cases
Midcycle
Premenstrual
1 2 3 4 5
35.8 37.1 34.2 32.6 33.5
34.1 36.3 36.1 32.0 34.1
Mean value
34.2
34.1*
a Expressed as benzaldehyde nanomoles formed Img proteimhr. * Statistically insignificant difference, Students t-test. TABLE PLATELET
MAO
ACTIVITY
IN MEN
2
AND WOMEN
OF THE CONTROL
Number of cases
Mean age (Yeats)
15 15
45.8 46.2
Women Men
GROUP
MAO activity 38.6 ” 5.8 39.6 2 4.2*
a Represents the mean 2 SEM for each group expressed as benzaldehyde formed/mg proteimhr. * Statistically insignificant difference, Students t-test. TABLE PLATELET
Controls Unipolar Bipolar
MAO ACTIVITY
IN PATIENTS
nanomoles
3 WITH CYCLOPHRENIC
DEPRESSION
Number of cases
Mean age (years)
MAO activity
30 35 13
46.0 49.3 48.7
39.1 k 5.0 45.0 ” 9.2* 22.9 k 7.9**
D Represents the mean k SEM for each group expressed as benzaldehyde nanomoles formed/mg proteinlhr. * 0.001 < P < 0.005 compared with controls. ** P < 0.001 compared with controls.
350
LANDOWSKI
ET Al
lower than that measured in controls (39.1 ? 5.6 nmoleimg protein/hr; P < 0.001). or in the unipolar depression group (45.0 !I 9.2 nmole/mg protein/hr; P < 0.001). The MAO activity in the latter group was significantly higher than it was in the control (0.005 < P < 0.001). No statistically significant differences were found between the men and women of the above-mentioned groups. Figure 1 shows the dispersion of the MAO activity in platelets of the single patients of each group. It suggests that the only characteristic of the bipolar depressed patients which differentiates them from the other groups is a decrease in MAO activity. Figure 2 shows that activity of the enzyme from bipolar depressed patients was reduced while the depressive episode was still present, even if the clinical depressive symptoms had disappeared owing to specific treatment. It reached the values of the controls only during spontaneous remission. Recurrence or absence of clinical depressive symptoms after cessa-
I Control
I
FIG. I Blood platelets 0 men I.
MAO
activity
I ~nlpolnr
in patients
I BiPCll~f
with cyclophrenic
depression
: I) women.
CYCLOPHRENIC
DEPRESSIVE
SYNDROMES
351
t
FIG. 2. Changes in blood platelets MAO activity in bipolar depressed patients in the coone of treatment and during the period of spontaneous remission.
tion of medication with tricyclic antidepressant agents (amitriptyline, imipramine) showed if the depressive episode was still present or whether spontaneous remission had set in. It is known that cortisol inhibits MAO activity of some organsin vivo (16, 17) and in vitro (17). In our experimental conditions, cortisol (Hydrocortisone Fluka) in concentrations of up to 5 M in vitro did not affect the activity of the platelet enzyme in any of the groups investigated. DISCUSSION
In contrast to the results of Murphy and Weiss (lo), the range of our results in the different groups has shown that the decrease of enzyme activity in bipolar depressed patients seemed to be characteristic of these patients and permitted their differentiation from unipolar depressed patients and from controls. This may be due to the greater homogeneity of unipolar depressed patients group investigated by us. They we:e included in the group if they experienced at least three depressive episodes. The differences described here seem, however, to be related to the use of different substrates, namely tryptamine by Murphy and Weiss, and benzylamine by us. A different monoamine oxidase, i.e., plasma monoamine oxidase, shows either significant variations in activity (18) or none (19) at all during the menstrual cycle, according to whether the substrate is tryptamine or benzylamine. When benzylamine is used as substrate, no sig-
352
LANDOWSKI
ET AL
nificant variations in MAO activity are observed in blood platelets during the menstrual cycle (19), as has been confirmed in our investigations. We did not determine in our study whether similar variations occurred with tryptamine. Severina (11) hypothesized the presence of two sites in the active center of MAO, the hydrophobic and the hydrophillic, with one of which the substrate reacts according to its chemical structure. It is presumed that benzylamine would react only with the hydrophobic site. As compared with benzylamine. tryptamine has more of a hydrophillic character. It can be supposed to react both with the hydrophobic and the hydrophillic sites of the active center of the enzyme. The fact that when tryptamine is used as substrate, the enzyme activity in the bipolar depressive group in many cases corresponds to that encountered in unipolar depressed patients and in controls, while it does not when benzylamine is used, suggests that reduced MAO activity in blood platelets from bipolar depressed patients is primarily related to the hydrophobic site of the active enzyme center. MAO activity in blood platelets from bipolar depressed patients remains reduced when the depressive episode is still present. even though clinical depressive symptoms have decreased under treatment with tricyclic antidepressant agents. Only during spontaneous remission is it equal to the values of the controls. This provides evidence that the site of action of tricyclic antidepressant drugs is further away from the primary cause of bipolar depression than is the mechanism resulting in a decrease of MAO activity in blood platelets. In this context, the absence of similar changes in the activity of the enzyme in unipolar depressed patients supports the idea that there exist separate mechanisms associated with the depressive episode in the two basic forms of cyclophrenia. It is not known whether the decrease of MAO activity in blood platelets from bipolar depressed patients is correlated with the pathogenesis of the depressive syndrome. MAO plays an essential role in the activity of at least some of the central monoaminergic systems (20, 21). Their dysfunction is pathogenetically linked to affective disorders (22. 23). The differences revealed in the present study in the activity of the platelet enzyme are in agreement with investigations in vim, which have shown the decrease of this activity in bipolar depression and increase in unipolar depression (IO, 24). All this supports the supposition that the platelet enzyme is similar to the monoamine oxidases which in the human body play an essential role in the inactivation of biogenic amines. The degree of similarity between the platelet enzyme and brain MAO is unknown. We do not know whether there is a decrease of brain MAO activity of bipolar depressed patients. Schwartz et N/. (25) reported that there was no significant reduction in MAO activity in post-mortem brain specimens from schizophrenic patients
CYCLOPHRENIC
DEPRESSIVE
353
SYNDROMES
as compared to that from normal controls. However, there was the decrease of MAO activity in blood platelets from schizophrenic patients (26). SUMMARY
Benzylamine was used as substrate to determine MAO activity in 13 bipolar depressed patients, 35 unipolar depressed patients, and 30 controls. The differences in enzyme activity found in the groups investigated were statistically significant. Decrease of MAO activity in bipolar depressed patients seems to be characteristic of that group and related to the presence of the depressive episode. Decrease of enzyme activity in these patients seems to be related mainly to the hydrophobic affinity of the enzyme to the substrate. ACKNOWLEDGMENT This work is supported by Polish Academy of Sciences-Grant
No. 09.4. I.
REFERENCES 1. Angst, J., in “Depressive Zestande. Erkennung. Bewertung, Behandlung” (P. Kielholz, Ed.), p. 28. Verlag Hans Huber, Bern, 1972. 2. Perris, C., Behav. Neuropsychiat. 1, 17 (1969). 3. Pert-is, C., Acta Psychiat. Stand. (Suppl. 42) 194, 7 (1966). 4. Winokur, G., J. Nerv. Ment. Dis. 156, 82 (1973). 5. Woodruff, R. A. Jr., Guze, S. B., and Clayton, P. J., Brit. J. Psychiat. 119, 33 (1971). 6. Goodwin, F. K., Murphy, D. L., Dunner, D. L., and Bunney, W. E., Jr., Amer. J. Psychiat.
129, 44 (1972).
7. Barge, G. F., Buchasbaum. M., Goodwin, F., Murphy, D., and Silverman. J. ,Arch. Gen. Psychiat. 24, 501 (1971). 8. Murphy, D.,Brodie. H.,Goodwin, F.,andBunney, W.,Nature(London~229,135(1971). 9. Dunner, D., Goodwin, F., Gershon, E., Murphy, D.. and Bunney, W., Arch. Gen. Psychiat.
26, 360 (1972).
IO. 11. 12. 13.
Murphy, D. L.. and Weiss, R., Amer. J. Psychiat. 128, 1351 (1972). Severina, I. S., Eur. J. Biochem. 38, 239 (1973). Severina, I. S., and Zhivotova. N. I., Biokhimiya 38, 202 (1973). Shulman, N. R., Marder, V. J., Hiller, M. C., and Collier, E. M., in “Progress in Hematology” Vol. 4, p. 222. C. V. Moore and E. B. Brown, Eds.. Grune and Straton, New York, 1964. 14. Robinson, D. S., Lovenberg. W.. Keiser. H., and Sjoerdsma. A., Biochem. Pharmacol. 17, 109 (1968).
15. 16. 17. 18.
Gornall, A. G.. Bardawill, C. J., and David, M. M., J. Biol. Chem. 177, 751 (1949). Parve& H.. and Parvez, S., Experientia 28, 1330 (1972). Parvez, H., and Parvez, S.. J. Neurochem. 20, 1011 (1973). Klaiber, E. L., Kobayashi, Y., and Broverman, D. M., Proceedings ofthe 49th Meeting of the Endocrine Society, 85, 1967. 19. Gilmore. N. J., Robinson, D. S., Nies, A., Sylwester. D., and Ravaris, C. L., J. Psychosom.
Res.
15, 215 (1971).
20. Carlsson, A., Bedard, P., Davis, J. N.. Kehr, W., Lindqvist. M., and Magnusson, T., in “Pharmacology and the Future of Man.” Vol. 4, p. 286. S. Krager, Basel, 1972.
354 ?I. 22. 23. 24. 25.
LANDOWSKI
ET AI
Grahame-Smith. D. G.. ./. Ncr,roc~he~z. 18, 103 ( 1971). Schildkraut, J. J.. Amer. J. Pswhicrf. 122, 509 (1965). Coppen. A.. Brit. .I. Pcwhitrr. '113, 1237 (1967). Sandier. M..J. P/~~~n~tro~l. (Ptrris) (Sfrppl. 1.) 5, IX I lY741. Schwartz. M. A., Aikens, A. M.. and Wyatt. R. J, .~.c~~,/r~,pllcr,-,,~~l~,o/f,pitr (Berli~i 38, 3 IY (1974). 26. Murphy, D. L.. and Wyatt. R. J.. Ntr/r,,u , /,on&rl~. 238, 325 (1972).
MEDICINE
14, 347-354 (1975)
Monoamine Oxidase Activity in Blood Platelets from Patients with Cyclophrenic Depressive Syndromes JERZY LANDOWSKI, Departments
WIESZAWA
of Psychiatry Medical
UYSIAK,
AND STEFAN
and Clinical Biochemistry, Academy, 80-21 I Gdatisk,
Institute Poland
ANGIELSKI of Pathology,
Received March 21. 1975
Genetic and clinical investigations (l-5) have made it possible to distinguish between two basic forms of cyclophrenia, the bipolar and the unipolar. The differences are also of pharmacological (6), neurophysiological(7), and biochemical (8, 9) nature and are related, among others, to MAO activity in blood platelets, which differs in bipolar depressed patients from that in unipolar depressed patients (10). It was demonstrated in investigations in which tryptamine was used as substrate for the enzyme. On the basis of Severma’s investigations (11, 12)) it may be suggested that some of the observed changes in monoamine oxidase activity (MAO) could be related to the chemical structure of the substrate used. It has, therefore, seemed of interest to use a substrate other than tryptamine to compare the activities of the platelet enzyme in the two basic groups of cyclophrenic depression. In this study we used benzylamine which is more hydrophobic than tryptamine. METHODS AND MATERIALS
MAO activity in blood platelets was studied in 48 patients hospitalized with diagnose of cyclophrenic depression (13 bipolar, 35 unipolar). In the group of bipolar depression (six women and seven men), were included patients with a history of at least one manic episode requiring treatment. The group of unipolar depression (20 women and 15 men), included patients who fulfilled the Pert-is criterion (2) and had at least three depressive episodes with absence of the manic or the hypomanic. The activity of the enzyme was determined during peak intensity of clinical depressive symptoms. The controls were patients (15 women and 15 men) with disorders of nonpsychotic nature (neurosis, brain organic damage). The patients received no medication for at least 1 week prior to the start of the study. Mean ages in the different groups were: controls-46.0 years, bipolar48.7, and unipolarA9.3. 341 Copyright 0 1975 by Academic Press. Inc. All rights of reproduction in any form reserved.
348
LANDOWSKI
ET AI
Blood samples were collected from fasting overnight patients at 8 AM into plastic test tubes containing 0.1 mmole EDTA. A suspension of blood platelets was obtained from 20 ml of whole blood by the method of Shulman et al. (13) in modification of Robinson et (11. (14). The final blood platelets residue was suspended in 1.1 ml of saline with addition of Triton X-100 at final concentration of 0.5%. MAO activities in blood platelets were determined by the method of Robinson et al. (14) with benzylamine as substrate. Incubation mixture contained in final volume of 1.5 ml:0.24 mmole of potassium phosphate buffer, pH = 7.2, 12 pm of benzylamine, and a blood platelets preparation corresponding to 0.4-0.5 mg of protein. The reaction was carried out at 37°C for 2 hr and was stopped by addition of 0.15 ml 6% HClO,. The benzaldehyde formed as a product of the reaction was extracted into 2.0 ml of cyclohexane in which the absorption changes were measured spectrophotometrically at 242 nm wavelength. The activity of the enzyme was expressed as nmoles of benzaldehyde formed per milligram of protein per hour. The reaction rate measured by the amount of the benzaldehyde formed was linear with reaction time and proportional to the amounts of protein. The amount of protein was determined by the biuret method (15) with bovine serum albumin as standard. RESULTS MAO Activity in Blood Platelets the Menstrual Cycle
during
The activity of the enzyme was determined at the mid-cycle and on the last day of the menstrual cycle in women aged 25 to 33 yr, having regular menstrual cycles and not displaying any symptoms of hormonal disorder. Table 1 shows that there were no significant changes in MAO activity during the menstrual cycle. Therefore, the phase ofthe cycle was not taken into consideration in the further course of the study. Sex-Dependence
of MAO Activity
in Blood Platelets
Comparison of the activity ofthe enzyme between the men and women of the control group (Table 2) revealed no statistically significant differences. In the further course of the study, the men and women of the control group were therefore treated as one unit. MAO Activity in Blood Platelets from Patients with Cyclophrenic Depression
As can be seen in Table 3, the activity of the enzyme in bipolar depressed patients (22.9 _C 7.9 nmole/mg proteimhr) was statistically significantly
CYCLOPHRENIC
DEPRESSIVE TABLE
PLATELET
MAO ACTIVITY
SYNDROMES
349
1
IN WOMEN
DURING
THE MENSTRUAL
CYCLE
MAO activitp Number of cases
Midcycle
Premenstrual
1 2 3 4 5
35.8 37.1 34.2 32.6 33.5
34.1 36.3 36.1 32.0 34.1
Mean value
34.2
34.1*
a Expressed as benzaldehyde nanomoles formed Img proteimhr. * Statistically insignificant difference, Students t-test. TABLE PLATELET
MAO
ACTIVITY
IN MEN
2
AND WOMEN
OF THE CONTROL
Number of cases
Mean age (Yeats)
15 15
45.8 46.2
Women Men
GROUP
MAO activity 38.6 ” 5.8 39.6 2 4.2*
a Represents the mean 2 SEM for each group expressed as benzaldehyde formed/mg proteimhr. * Statistically insignificant difference, Students t-test. TABLE PLATELET
Controls Unipolar Bipolar
MAO ACTIVITY
IN PATIENTS
nanomoles
3 WITH CYCLOPHRENIC
DEPRESSION
Number of cases
Mean age (years)
MAO activity
30 35 13
46.0 49.3 48.7
39.1 k 5.0 45.0 ” 9.2* 22.9 k 7.9**
D Represents the mean k SEM for each group expressed as benzaldehyde nanomoles formed/mg proteinlhr. * 0.001 < P < 0.005 compared with controls. ** P < 0.001 compared with controls.
350
LANDOWSKI
ET Al
lower than that measured in controls (39.1 ? 5.6 nmoleimg protein/hr; P < 0.001). or in the unipolar depression group (45.0 !I 9.2 nmole/mg protein/hr; P < 0.001). The MAO activity in the latter group was significantly higher than it was in the control (0.005 < P < 0.001). No statistically significant differences were found between the men and women of the above-mentioned groups. Figure 1 shows the dispersion of the MAO activity in platelets of the single patients of each group. It suggests that the only characteristic of the bipolar depressed patients which differentiates them from the other groups is a decrease in MAO activity. Figure 2 shows that activity of the enzyme from bipolar depressed patients was reduced while the depressive episode was still present, even if the clinical depressive symptoms had disappeared owing to specific treatment. It reached the values of the controls only during spontaneous remission. Recurrence or absence of clinical depressive symptoms after cessa-
I Control
I
FIG. I Blood platelets 0 men I.
MAO
activity
I ~nlpolnr
in patients
I BiPCll~f
with cyclophrenic
depression
: I) women.
CYCLOPHRENIC
DEPRESSIVE
SYNDROMES
351
t
FIG. 2. Changes in blood platelets MAO activity in bipolar depressed patients in the coone of treatment and during the period of spontaneous remission.
tion of medication with tricyclic antidepressant agents (amitriptyline, imipramine) showed if the depressive episode was still present or whether spontaneous remission had set in. It is known that cortisol inhibits MAO activity of some organsin vivo (16, 17) and in vitro (17). In our experimental conditions, cortisol (Hydrocortisone Fluka) in concentrations of up to 5 M in vitro did not affect the activity of the platelet enzyme in any of the groups investigated. DISCUSSION
In contrast to the results of Murphy and Weiss (lo), the range of our results in the different groups has shown that the decrease of enzyme activity in bipolar depressed patients seemed to be characteristic of these patients and permitted their differentiation from unipolar depressed patients and from controls. This may be due to the greater homogeneity of unipolar depressed patients group investigated by us. They we:e included in the group if they experienced at least three depressive episodes. The differences described here seem, however, to be related to the use of different substrates, namely tryptamine by Murphy and Weiss, and benzylamine by us. A different monoamine oxidase, i.e., plasma monoamine oxidase, shows either significant variations in activity (18) or none (19) at all during the menstrual cycle, according to whether the substrate is tryptamine or benzylamine. When benzylamine is used as substrate, no sig-
352
LANDOWSKI
ET AL
nificant variations in MAO activity are observed in blood platelets during the menstrual cycle (19), as has been confirmed in our investigations. We did not determine in our study whether similar variations occurred with tryptamine. Severina (11) hypothesized the presence of two sites in the active center of MAO, the hydrophobic and the hydrophillic, with one of which the substrate reacts according to its chemical structure. It is presumed that benzylamine would react only with the hydrophobic site. As compared with benzylamine. tryptamine has more of a hydrophillic character. It can be supposed to react both with the hydrophobic and the hydrophillic sites of the active center of the enzyme. The fact that when tryptamine is used as substrate, the enzyme activity in the bipolar depressive group in many cases corresponds to that encountered in unipolar depressed patients and in controls, while it does not when benzylamine is used, suggests that reduced MAO activity in blood platelets from bipolar depressed patients is primarily related to the hydrophobic site of the active enzyme center. MAO activity in blood platelets from bipolar depressed patients remains reduced when the depressive episode is still present. even though clinical depressive symptoms have decreased under treatment with tricyclic antidepressant agents. Only during spontaneous remission is it equal to the values of the controls. This provides evidence that the site of action of tricyclic antidepressant drugs is further away from the primary cause of bipolar depression than is the mechanism resulting in a decrease of MAO activity in blood platelets. In this context, the absence of similar changes in the activity of the enzyme in unipolar depressed patients supports the idea that there exist separate mechanisms associated with the depressive episode in the two basic forms of cyclophrenia. It is not known whether the decrease of MAO activity in blood platelets from bipolar depressed patients is correlated with the pathogenesis of the depressive syndrome. MAO plays an essential role in the activity of at least some of the central monoaminergic systems (20, 21). Their dysfunction is pathogenetically linked to affective disorders (22. 23). The differences revealed in the present study in the activity of the platelet enzyme are in agreement with investigations in vim, which have shown the decrease of this activity in bipolar depression and increase in unipolar depression (IO, 24). All this supports the supposition that the platelet enzyme is similar to the monoamine oxidases which in the human body play an essential role in the inactivation of biogenic amines. The degree of similarity between the platelet enzyme and brain MAO is unknown. We do not know whether there is a decrease of brain MAO activity of bipolar depressed patients. Schwartz et N/. (25) reported that there was no significant reduction in MAO activity in post-mortem brain specimens from schizophrenic patients
CYCLOPHRENIC
DEPRESSIVE
353
SYNDROMES
as compared to that from normal controls. However, there was the decrease of MAO activity in blood platelets from schizophrenic patients (26). SUMMARY
Benzylamine was used as substrate to determine MAO activity in 13 bipolar depressed patients, 35 unipolar depressed patients, and 30 controls. The differences in enzyme activity found in the groups investigated were statistically significant. Decrease of MAO activity in bipolar depressed patients seems to be characteristic of that group and related to the presence of the depressive episode. Decrease of enzyme activity in these patients seems to be related mainly to the hydrophobic affinity of the enzyme to the substrate. ACKNOWLEDGMENT This work is supported by Polish Academy of Sciences-Grant
No. 09.4. I.
REFERENCES 1. Angst, J., in “Depressive Zestande. Erkennung. Bewertung, Behandlung” (P. Kielholz, Ed.), p. 28. Verlag Hans Huber, Bern, 1972. 2. Perris, C., Behav. Neuropsychiat. 1, 17 (1969). 3. Pert-is, C., Acta Psychiat. Stand. (Suppl. 42) 194, 7 (1966). 4. Winokur, G., J. Nerv. Ment. Dis. 156, 82 (1973). 5. Woodruff, R. A. Jr., Guze, S. B., and Clayton, P. J., Brit. J. Psychiat. 119, 33 (1971). 6. Goodwin, F. K., Murphy, D. L., Dunner, D. L., and Bunney, W. E., Jr., Amer. J. Psychiat.
129, 44 (1972).
7. Barge, G. F., Buchasbaum. M., Goodwin, F., Murphy, D., and Silverman. J. ,Arch. Gen. Psychiat. 24, 501 (1971). 8. Murphy, D.,Brodie. H.,Goodwin, F.,andBunney, W.,Nature(London~229,135(1971). 9. Dunner, D., Goodwin, F., Gershon, E., Murphy, D.. and Bunney, W., Arch. Gen. Psychiat.
26, 360 (1972).
IO. 11. 12. 13.
Murphy, D. L.. and Weiss, R., Amer. J. Psychiat. 128, 1351 (1972). Severina, I. S., Eur. J. Biochem. 38, 239 (1973). Severina, I. S., and Zhivotova. N. I., Biokhimiya 38, 202 (1973). Shulman, N. R., Marder, V. J., Hiller, M. C., and Collier, E. M., in “Progress in Hematology” Vol. 4, p. 222. C. V. Moore and E. B. Brown, Eds.. Grune and Straton, New York, 1964. 14. Robinson, D. S., Lovenberg. W.. Keiser. H., and Sjoerdsma. A., Biochem. Pharmacol. 17, 109 (1968).
15. 16. 17. 18.
Gornall, A. G.. Bardawill, C. J., and David, M. M., J. Biol. Chem. 177, 751 (1949). Parve& H.. and Parvez, S., Experientia 28, 1330 (1972). Parvez, H., and Parvez, S.. J. Neurochem. 20, 1011 (1973). Klaiber, E. L., Kobayashi, Y., and Broverman, D. M., Proceedings ofthe 49th Meeting of the Endocrine Society, 85, 1967. 19. Gilmore. N. J., Robinson, D. S., Nies, A., Sylwester. D., and Ravaris, C. L., J. Psychosom.
Res.
15, 215 (1971).
20. Carlsson, A., Bedard, P., Davis, J. N.. Kehr, W., Lindqvist. M., and Magnusson, T., in “Pharmacology and the Future of Man.” Vol. 4, p. 286. S. Krager, Basel, 1972.
354 ?I. 22. 23. 24. 25.
LANDOWSKI
ET AI
Grahame-Smith. D. G.. ./. Ncr,roc~he~z. 18, 103 ( 1971). Schildkraut, J. J.. Amer. J. Pswhicrf. 122, 509 (1965). Coppen. A.. Brit. .I. Pcwhitrr. '113, 1237 (1967). Sandier. M..J. P/~~~n~tro~l. (Ptrris) (Sfrppl. 1.) 5, IX I lY741. Schwartz. M. A., Aikens, A. M.. and Wyatt. R. J, .~.c~~,/r~,pllcr,-,,~~l~,o/f,pitr (Berli~i 38, 3 IY (1974). 26. Murphy, D. L.. and Wyatt. R. J.. Ntr/r,,u , /,on&rl~. 238, 325 (1972).
